Figure 8. Reinduction of Ets1 in older mice leads to a less severe phenotype.

(A) Schematic representation of a typical time course for the re-induction studies. Some BT mice underwent transgene induction at an early age (4–6 weeks) and were then rescued by restoring the Dox diet to suppress transgene expression. The same mice were later reinduced by withdrawing Dox supplementation for an extended time course. After prolonged transgene induction, these re-induced mice developed discrete lesions (papillomatous or ulcerative, white arrows). (B) Hematoxylin and eosin stained sections below the time course indicate typical epidermal morphology at each stage of the induction process. (C) Trichrome staining of the lesions obtained from reinduced BT mice demonstrates downgrowths into the dermis. Boxed areas show regions of thin chords of invading keratinocytes.